In commercial operations where very large numbers of similar documents must be produced and mailed, a very small savings per document will translate into a large saving over the many documents. Examples of such documents are payroll checks, direct mail solicitations, 1099 forms, invoices, business statements, coupons, sales pieces, student grade reports, membership notices, and so forth. There are many other examples.
Traditional expenses for such operations include the cost of printing the documents, and labor for such tasks as folding, stuffing envelopes, and addressing.
In recent years, especially with the rapid growth of computer control techniques, equipment has been developed to produce self-mailers from single sheets. This process takes a single sheet and folds it in concert with an application of adhesive (or activation of existing areas of adhesive), perforates the edges for ease of opening, and seals the sheet into a unit known in the art as a self-mailer. The self-mailer becomes its own envelope, and no stuffing of envelopes is needed.
There are a number of different types of self-mailers known in the art and a number of different procedures for making them. For example, a type of adhesive that may later be activated with water may be applied to single sheets, which are then fed automatically through a laser printer, and then to a self-mailer machine that moistens the adhesive strips, folds the sheets, perforates the sheets appropriately for the particular form, and seals the unit together as a self-mailer. This kind of adhesive is the type used for flaps of most envelopes, and thus is familiar to most everyone.
The moistenable adhesive approach is used by manufacturers who judge it too difficult and troublesome to apply adhesive at the self-mailer machine; and if not done properly, applying glue at the self-mailer machine can be truly troublesome.
The pre-gluing approach, however, has its own drawbacks. For example, applying moistenable adhesive to the single sheets cannot normally be done in concert with printing, because the adhesive must be allowed to cure before coming in contact with the printing equipment or even other single sheets. Moreover, even cured, the moistenable adhesive is often not compatible with printing equipment, especially laser printers which operate by applying a high local temperature to the paper upon which printing is to be done. The high temperature often softens the adhesive and renders it tacky, creating jams and cleaning problems. Further, moistening the adhesive in the self-mailer machine can be just as troublesome as applying adhesive, because water can get onto regions where it isn't wanted and can also damage the equipment. Another drawback is that moistenable adhesive becomes more of a problem in warm and damp climates, such as in countries close to the equator.
The approach of moistenable adhesive to avoid applying adhesive at the self-mailer machine is often, therefore, more expensive than the problems it is meant to avoid. The application of the moistenable adhesive is a separate operation with its own attendant costs, the problems the adhesive causes in printing equipment, particularly laser printing equipment, slows down the printing operation making it more expensive, and no balancing savings is realized at the self-mailer machine.
Typically a form folding and gluing apparatus as described above has guide plates arranged in concert with rollers providing for guiding and folding paper sheets as described in more detail below. The guide plates in such machines typically have cut-out areas (openings) over which glue guns (actuators) are mounted in a manner to allow glue to be applied through the openings onto sheets guided between the plates. In some cases the actuators are positioned to apply glue along an edge of a moving sheet as the sheet passes the actuator. In other cases actuators are positioned to apply a spot or spots of glue along an edge or fold line at right angles to the direction of travel of a sheet through the apparatus. It is the latter case with which the present invention is principally concerned.
Conventional machines are designed with specific opening as described above, and mountings are designed to position the actuators with little or no flexibility of position. As a result only a limited range of different sorts of mailers may be processed with a particular set of guide plates and associated actuator mountings.
What is needed is a modular and very adaptable apparatus allowing sheets to be reliably guided, actuators to mounted at essentially any position relative to processed sheets, thereby allowing glue to be applied at a much broader range of positions, and also allowing paper stops, which determine position of folds, to be adjusted without having to adjust actuator positions independently. The invention herein described provides such an apparatus, wherein moveable rails replace the traditional guide plates, and actuator mountings provide for essentially universal placement relative to sheet position.